procutil: make stream detection in make_line_buffered more correct and strict
In make_line_buffered(), we don’t want to wrap the stream if we know that lines
get flushed to the underlying raw stream already.
Previously, the heuristic was too optimistic. It assumed that any stream which
is not an instance of io.BufferedIOBase doesn’t need wrapping. However, there
are buffered streams that aren’t instances of io.BufferedIOBase, like
Mercurial’s own winstdout.
The new logic is different in two ways:
First, only for the check, if unwraps any combination of WriteAllWrapper and
winstdout.
Second, it skips wrapping the stream only if it is an instance of io.RawIOBase
(or already wrapped). If it is an instance of io.BufferedIOBase, it gets
wrapped. In any other case, the function raises an exception. This ensures
that, if an unknown stream is passed or we add another wrapper in the future,
we don’t wrap the stream if it’s already line buffered or not wrap the stream
if it’s not line buffered. In fact, this was already helpful during development
of this change. Without it, I possibly would have forgot that WriteAllWrapper
needs to be ignored for the check, leading to unnecessary wrapping if stdout is
unbuffered.
The alternative would have been to always wrap unknown streams. However, I
don’t think that anyone would benefit from being less strict. We can expect
streams from the standard library to be subclassing either io.RawIOBase or
io.BufferedIOBase, so running Mercurial in the standard way should not regress
by this change. Py2exe might replace sys.stdout and sys.stderr, but that
currently breaks Mercurial anyway and also these streams don’t claim to be
interactive, so this function is not called for them.
# fetch.py - pull and merge remote changes
#
# Copyright 2006 Vadim Gelfer <vadim.gelfer@gmail.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
'''pull, update and merge in one command (DEPRECATED)'''
from mercurial.i18n import _
from mercurial.node import short
from mercurial import (
cmdutil,
error,
exchange,
hg,
lock,
pycompat,
registrar,
)
from mercurial.utils import (
dateutil,
urlutil,
)
release = lock.release
cmdtable = {}
command = registrar.command(cmdtable)
# Note for extension authors: ONLY specify testedwith = 'ships-with-hg-core' for
# extensions which SHIP WITH MERCURIAL. Non-mainline extensions should
# be specifying the version(s) of Mercurial they are tested with, or
# leave the attribute unspecified.
testedwith = b'ships-with-hg-core'
@command(
b'fetch',
[
(
b'r',
b'rev',
[],
_(b'a specific revision you would like to pull'),
_(b'REV'),
),
(b'', b'edit', None, _(b'invoke editor on commit messages')),
(b'', b'force-editor', None, _(b'edit commit message (DEPRECATED)')),
(b'', b'switch-parent', None, _(b'switch parents when merging')),
]
+ cmdutil.commitopts
+ cmdutil.commitopts2
+ cmdutil.remoteopts,
_(b'hg fetch [SOURCE]'),
helpcategory=command.CATEGORY_REMOTE_REPO_MANAGEMENT,
)
def fetch(ui, repo, source=b'default', **opts):
"""pull changes from a remote repository, merge new changes if needed.
This finds all changes from the repository at the specified path
or URL and adds them to the local repository.
If the pulled changes add a new branch head, the head is
automatically merged, and the result of the merge is committed.
Otherwise, the working directory is updated to include the new
changes.
When a merge is needed, the working directory is first updated to
the newly pulled changes. Local changes are then merged into the
pulled changes. To switch the merge order, use --switch-parent.
See :hg:`help dates` for a list of formats valid for -d/--date.
Returns 0 on success.
"""
opts = pycompat.byteskwargs(opts)
date = opts.get(b'date')
if date:
opts[b'date'] = dateutil.parsedate(date)
parent = repo.dirstate.p1()
branch = repo.dirstate.branch()
try:
branchnode = repo.branchtip(branch)
except error.RepoLookupError:
branchnode = None
if parent != branchnode:
raise error.Abort(
_(b'working directory not at branch tip'),
hint=_(b"use 'hg update' to check out branch tip"),
)
wlock = lock = None
try:
wlock = repo.wlock()
lock = repo.lock()
cmdutil.bailifchanged(repo)
bheads = repo.branchheads(branch)
bheads = [head for head in bheads if len(repo[head].children()) == 0]
if len(bheads) > 1:
raise error.Abort(
_(
b'multiple heads in this branch '
b'(use "hg heads ." and "hg merge" to merge)'
)
)
path = urlutil.get_unique_pull_path(b'fetch', repo, ui, source)[0]
other = hg.peer(repo, opts, path)
ui.status(_(b'pulling from %s\n') % urlutil.hidepassword(path))
revs = None
if opts[b'rev']:
try:
revs = [other.lookup(rev) for rev in opts[b'rev']]
except error.CapabilityError:
err = _(
b"other repository doesn't support revision lookup, "
b"so a rev cannot be specified."
)
raise error.Abort(err)
# Are there any changes at all?
modheads = exchange.pull(repo, other, heads=revs).cgresult
if modheads == 0:
return 0
# Is this a simple fast-forward along the current branch?
newheads = repo.branchheads(branch)
newchildren = repo.changelog.nodesbetween([parent], newheads)[2]
if len(newheads) == 1 and len(newchildren):
if newchildren[0] != parent:
return hg.update(repo, newchildren[0])
else:
return 0
# Are there more than one additional branch heads?
newchildren = [n for n in newchildren if n != parent]
newparent = parent
if newchildren:
newparent = newchildren[0]
hg.clean(repo, newparent)
newheads = [n for n in newheads if n != newparent]
if len(newheads) > 1:
ui.status(
_(
b'not merging with %d other new branch heads '
b'(use "hg heads ." and "hg merge" to merge them)\n'
)
% (len(newheads) - 1)
)
return 1
if not newheads:
return 0
# Otherwise, let's merge.
err = False
if newheads:
# By default, we consider the repository we're pulling
# *from* as authoritative, so we merge our changes into
# theirs.
if opts[b'switch_parent']:
firstparent, secondparent = newparent, newheads[0]
else:
firstparent, secondparent = newheads[0], newparent
ui.status(
_(b'updating to %d:%s\n')
% (repo.changelog.rev(firstparent), short(firstparent))
)
hg.clean(repo, firstparent)
p2ctx = repo[secondparent]
ui.status(
_(b'merging with %d:%s\n') % (p2ctx.rev(), short(secondparent))
)
err = hg.merge(p2ctx, remind=False)
if not err:
# we don't translate commit messages
message = cmdutil.logmessage(ui, opts) or (
b'Automated merge with %s' % urlutil.removeauth(other.url())
)
editopt = opts.get(b'edit') or opts.get(b'force_editor')
editor = cmdutil.getcommiteditor(edit=editopt, editform=b'fetch')
n = repo.commit(
message, opts[b'user'], opts[b'date'], editor=editor
)
ui.status(
_(b'new changeset %d:%s merges remote changes with local\n')
% (repo.changelog.rev(n), short(n))
)
return err
finally:
release(lock, wlock)